[danielhv]

So Im clecoing all the ribs to both the spars on the wings... got one done, and then half way through the other.... problem is, the ribs seem like they are facing the wrong way.... but if I flip them around, it wont match the plans.

Let me try to explain what im seeing... the trailing edges of the ribs have a little tab that sits down beneath the flange of the rear spar. The left wing was fine. But the tabs on the right wing are on the opposite side of the right rear spar flange...

Here are some pics:

 

[rvbuilder2002]

Look carefully at the plans while evaluating teh ribs as follows.

When the plans say to use a W-7XXR rib in a specific location it means a rib that when held vertically in front of you, fwd end away from you and bottom flange down (side with the fwd tooling hole closer to the bottom), the flanges point to your right.

So...any rib when viewed from the top leading edge away from you, that has the flanges going to the right is an "R" rib. Any with the flanges going to the left is an "L" rib.
L's and R's are used interchangeably on both wings. Also be sure to use the alternate part #'s in the correct locations...they are thicker material. The inboard most (root) main rib for example.

 

[az_gila]

It's a bit hard to see...

...from the first picture, but it looks like your Right wing ribs may be upside down.

Look carefully and make sure left and right are true mirror images of each other, assuming you have the roots at the same end - which it looks like from the pics.

 

[Webb]

Check the direction the ribs are facing

Daniel,

Best I can tell from the picture, it looks like the flanges of the ribs that attach to the skins are facing the same direction.

Go back and look at the plans. Notice the rib flanges face one another at different points on the wings. This is so you can get your hand inside the inspection hole and get a bucking bar on them.

[ _ ] [ _ ] [ _ ] Like this. The underscore is the inspection hole.

Not like this [ _ [ [ _ [ [ _ [

Once you get them oriented, they will all work out like they are supposed too.

Hope this helps.

 

[Geico266]

[ _ ] [ _ ] [ _ ] Like this. The underscore is the inspection hole.

Not like this [ _ [ [ _ [ [ _ [

Once you get them oriented, they will all work out like they are supposed too.

Web, that was so simple even I understood it! Man, I'm about ready to order a tail kit! I can do this!

 

[danielhv]

Look carefully at the plans while evaluating teh ribs as follows.

When the plans say to use a W-7XXR rib in a specific location it means a rib that when held vertically in front of you, fwd end away from you and bottom flange down (side with the fwd tooling hole closer to the bottom), the flanges point to your right.

So...any rib when viewed from the top leading edge away from you, that has the flanges going to the right is an "R" rib. Any with the flanges going to the left is an "L" rib.
L's and R's are used interchangeably on both wings. Also be sure to use the alternate part #'s in the correct locations...they are thicker material. The inboard most (root) main rib for example.

Im pretty sure I have that part right. I marked every one with a perm marker and many still have the label from vans. When I marked them, I marked them with the same # as the label said.

As far as alternating, I did alternate the ribs... If you look closely at the pics where it shows the whole wing, along the rear spar you can see the flange of every other rib...

Second... if everything (tooling holes on both leading and trailing edge of ribs) line up on the left wing, and all the holes the rear spar line up... doesn't that take out all the guess work as to rather or not something is wrong??

 

[morlino]

It was confusing at first because your right wing is on the left side of the picture....

Take the rear spar off completely and look down the wing through the smallest set of lightening holes. It looks like your right wing root rib is oriented correctly but I think Gil is correct and the rest of them are mixed up and flipped around.

Should look like the bottom picture here: http://rvproject.com/20020519.html

Counting the root rib as #1 it looks like maybe you've got #2 and #4 switched.

Oh yeah, and stop working so fast... you're gonna be ahead of me real soon

 

[LettersFromFlyoverCountry]

This is one of those times when it's good to think about WHY something orients one way or the other. In this case, it's all about access when riveting with the skins partially on. Put the bottom skin on , then reach inside the access holes... each rib should be oriented so that the flanges are easily available to you to buck the rivets by sticking your hand in the access hole.

If you're feeling the web of a rib, it's turned the wrong way.

 

[danielhv]

I just went out there and pulled about 4 ribs off the right spar, and the part #'s I wrote on them DO match the part # lable vans put on there.... but even if I switched ribs betweent he two wings... it still wouldn't work. The little "cut tab" on the flange of the ribs is still on the wrong side for the rear spar ONLY ON THE RIGHT WING. It's almost like the rear spar is wrong... but even if I flipped it and riveted it the other side, its the same... So if the ribs are identical between the left and right wing (ie: left wing's W-711L is the same as the right wings W-711L) then something else is wrong... because ALL the ribs on the right wing are wrong. The only way to fix it is to make them face the opposite directions the plans call for! I dont get it.

 

[danielhv]

This is one of those times when it's good to think about WHY something orients one way or the other. In this case, it's all about access when riveting with the skins partially on. Put the bottom skin on , then reach inside the access holes... each rib should be oriented so that the flanges are easily available to you to buck the rivets by sticking your hand in the access hole.

If you're feeling the web of a rib, it's turned the wrong way.

This is not the case here... the flanges are facing the inspection covers on both sides. Just like Webb's depiction:

[ _ ] [ _ ] [ _ ]

 

[danielhv]

It was confusing at first because your right wing is on the left side of the picture....

Take the rear spar off completely and look down the wing through the smallest set of lightening holes. It looks like your right wing root rib is oriented correctly but I think Gil is correct and the rest of them are mixed up and flipped around.

Should look like the bottom picture here: http://rvproject.com/20020519.html

Counting the root rib as #1 it looks like maybe you've got #2 and #4 switched.

Oh yeah, and stop working so fast... you're gonna be ahead of me real soon

All of the tooling holes on both wings line up perfectly, with the exception of the W-710R rib on the right wing. it is off BUT it is also the only rib on the wing that has the little tab in the right spot. everything else lines up perfectly with the exception of the little tabs being on the wrong side.

 

[N941WR]

Daniel,

Two things come to mind as I look at your pictures.

1. Do you have the main spars on the correct side? (I remember reading about some guy who riveted in his spars upside down, so I have to ask.)
Remember, the bottom side of the main spar will have extra holes in the flange for the inspection panels.

2. Is it possible you riveted the stiffener to the wrong side of the aft spar? In other words, made both of them exactly the same rather than mirror images of each other?

 

[danielhv]

It was confusing at first because your right wing is on the left side of the picture....

Take the rear spar off completely and look down the wing through the smallest set of lightening holes. It looks like your right wing root rib is oriented correctly but I think Gil is correct and the rest of them are mixed up and flipped around.

If I flip them around, they will face the opposite direction depicted on the plans... thats whats confusing me. the part numbers are correct. I promise. I even cross checked vans part number tag with the whole point the leading edge away, flange side closest to the tooling hole towards the ground, which way is the flange facing test. Everything is where it is supposed to be, and facing the correct direction. The tabs are on the wrong side. all of them (except the root rib). If I had them out of order, wouldn't some be on one side and some be on the other instead of ALL of them being on the wrong side?

 

[danielhv]

Daniel,

Two things come to mind as I look at your pictures.

1. Do you have the main spars on the correct side? (I remember reading about some guy who riveted in his spars upside down, so I have to ask.)
Remember, the bottom side of the main spar will have extra holes in the flange for the inspection panels.

2. Is it possible you riveted the stiffener to the wrong side of the aft spar? In other words, made both of them exactly the same rather than mirror images of each other?

1. yes sir, double checked. If you look close enough, you can see the platenuts for the inspection covers in the 2nd and 3rd pictures on the original post... they are on the bottom closest to the rear spar.

2. i thought the same thing... but it doesn't matter which way you rivet it, it will be the same. The spar is in the shape of a Z. Turn a Z upside down and its still a Z. The flanges will be pointing in the same direction regardless of what side the stiffners are riveted on.

 

[N941WR]

...
2. i thought the same thing... but it doesn't matter which way you rivet it, it will be the same. The spar is in the shape of a Z. Turn a Z upside down and its still a Z. The flanges will be pointing in the same direction regardless of what side the stiffners are riveted on.

OK, did they send you two identical aft spars? Aren't they supposed to be different numbers? (I don't have my plans in front of me.)

If this happened, the doublers would probably light right up and rivet on.

If those aft spars are interchangable, that might just be what is going on.

 

[Transporter]

Rear Spar

There's a definite orientation to the rear spar...the Z channel is not identical.

Take another look at your exploded ISO view (my drawing is 10A for both RV7/8 and shows the left wing). Take a look at the Rear Spar Rear View (at the bottom of the drawing):

The rivet lines running down the web of the spar are for the aileron gap fairing and flap brace. If you've flipped the channel the wrong way, two things will happen:
1. The rivet lines for these components won't match when you try to cleco/rivet later on.
2. The flange angles for the upper and lower skins won't match the angle of your skins as they join the flange. The flange angles match the airfoil.

Other comments regarding rib orientation apply: use this same ISO drawing to sort out the ribs.

Hope this helps,
Mike

 

[danielhv]

Daniel,

This should help.

Forget the tooling holes right now. They are in the middle of the rib and will line up.

I went back to your photos and you have some of the ribs flipped and probably on the wrong side of the plane.

The R and L ribs do NOT mean wing side. A 711R and a 711L does NOT mean left and right wing. It means they way the flang faces and will be located on the same wing. (I promise)

Look at drawing #9 and 10A. If you look closely, you will notice the flanges are pictured facing each other WHERE there is an inspection hole so you can get you arm in there and get a bucking bar on the rib.

Once you see this, you'll be fine. I would however, go back and check the orientation of every rib before you match drill the first hole.

Now, go have a beer and relax.

I understand the part about R & L not meaning R wing L wing... I DO have alternating ribs on each wing (W-711L & W-711R per the plans)

The flanges ARE facing each other where there is an inspection plate.

And the tooling holes I'm talking about being lined up are the ones that are offset to the left or right and are used in determining the L & R designation for each rib per vans instructions and as others have said on here as well... So they will only line up if the correct ribs are in the correct places and facing the correct direction...

 

[danielhv]

OK, did they send you two identical aft spars? Aren't they supposed to be different numbers? (I don't have my plans in front of me.)

If this happened, the doublers would probably light right up and rivet on.

If those aft spars are interchangable, that might just be what is going on.

hope not! what a PITA that would be... ill double check.

 

[Webb]

I SEE IT

I think I see it!!!!

Is it possible that you have the most inboard rib correct and you have left and right flipped forthe remaining 14 ribs?

 

[Webb]

not 14 but 12

Sorry, 12 ribs, not 14

For example you have #2 where #3 should be, # 4 and #5 switch, and so on.

IE - L and R are switched.

 

[danielhv]

There's a definite orientation to the rear spar...the Z channel is not identical.

Take another look at your exploded ISO view (my drawing is 10A for both RV7/8 and shows the left wing). Take a look at the Rear Spar Rear View (at the bottom of the drawing):

The rivet lines running down the web of the spar are for the aileron gap fairing and flap brace. If you've flipped the channel the wrong way, two things will happen:
1. The rivet lines for these components won't match when you try to cleco/rivet later on.
2. The flange angles for the upper and lower skins won't match the angle of your skins as they join the flange. The flange angles match the airfoil.

Other comments regarding rib orientation apply: use this same ISO drawing to sort out the ribs.

Hope this helps,
Mike

I just checked this, and the rear spars ARE correct... the top side of the spar has the flange pointing aft on both wings per the plans.

 

[danielhv]

Question... if I change all the -L's to -R's and vice versa for the RIGHT WING ONLY... it will orient everything the way it needs to be. Now I KNOW the parts are marked correctly as they are right now as they still have vans part # tag on them AND I checked each one using the method described in the plans... Will it be ok to switch all of them from R's to L's and from L's to R's??

 

[Lionclaw]

If I flip them around, they will face the opposite direction depicted on the plans...

Just a thought...

Since the left wing (on the 9 anyway) is the only one with a drawing, you have to reverse everything when you do the right wing. I think of my ribs in terms of facing inboard or outboard. The ribs in identical positions on both wings face opposite directions. If I recall correctly, this means on the right wing you need to use L ribs where Rs were used on the left, and R ribs where Ls were used.

Maybe it's something more complicated like the wrong parts? Figured I'd take a shot at the simple side...

 

[Webb]

Should be OK

L and R are mirror images and should be fine.

The 12 ribs I asked if the pairs were switched would do just that.

Dumb question - where you possibly standing on the wrong side of the wing when you clecoed?

 

[Don Jones]

Exactly!

Just a thought...

Since the left wing (on the 9 anyway) is the only one with a drawing, you have to reverse everything when you do the right wing. I think of my ribs in terms of facing inboard or outboard. The ribs in identical positions on both wings face opposite directions. If I recall correctly, this means on the right wing you need to use L ribs where Rs were used on the left, and R ribs where Ls were used.

Maybe it's something more complicated like the wrong parts? Figured I'd take a shot at the simple side...

I was thinking the exact same thing. The drawings on the 9 are for the left wing and I had to use R for L on the right wing. The 7 is probably the same way. Looks like switching "L" for "R" will straighten it out to me.

 

[Flying Scotsman]

If that solves it, and it sounds like it will, it's a common situation wrt plans showing only one side...you'll have to mentally modify the plans to use the right part for a symmetric assembly. Looking at my plans (7A), the left wing main ribs are, from inboard to outboard):

710R
711R
711R
711L
711L
711R
711L
711R
711L
711R
711L
712L
712L
712R

For the right wing, change all the Ls to Rs and Rs to Ls, to get

710L
711L
711L
711R
711R
711L
711R
711L
711R
711L
711R
712R
712R
712L

You'll need to do the same thing for nose ribs and fuel tank ribs, and there are no doubt many other places where only a "left" or "right" assembly is shown and the same situation applies.

Hope this helps and you got 'er figured out!

 

[danielhv]

I was thinking the exact same thing. The drawings on the 9 are for the left wing and I had to use R for L on the right wing. The 7 is probably the same way. Looks like switching "L" for "R" will straighten it out to me.

That worked... Man, I would have figured vans would have said something somewhere on the plans or something to let the builder know this. I didnt even see it mentioned on 3 other builders sites! Guess something that is simple and common sense to one is not to the other!

Thanks for the help guys... looks like I owe each of you a ride in my plane with backwards wings!!

 

[rvbuilder2002]

That worked... Man, I would have figured vans would have said something somewhere on the plans or something to let the builder know this. I didnt even see it mentioned on 3 other builders sites! Guess something that is simple and common sense to one is not to the other!

Thanks for the help guys... looks like I owe each of you a ride in my plane with backwards wings!!

I think they did (though it may not seem obvious). I believe it says to build the other wing as a mirror image of the first. Doing so switches the orientation of all the ribs.


Glad you figured it out.

 

[Webb]

Outstanding

Glad you got it figured out.

 

[N941WR]

Good to hear it was that simple and you didn't have to change parts, drill out rivets, etc.

 

[danielhv]

Good to hear it was that simple and you didn't have to change parts, drill out rivets, etc.

You and me both brother!!!!

Really though, thanks for all the help everybody. I don't see how so many have been built without the use of VAF!

-Daniel

 

[N941WR]

Daniel,

I believe, but don't know for sure, the reason Van's staggers the ribs is so that when you rivet on the bottom skin, the flanges are turned towards the inspection holes. This would allow you to buck all the ribs accessible from one hole, move to the next hole and do the same. Notice how the ribs at each end have their flanges pointing towards their respective ends as well.

Those guys at Van's are very smart that way so I wouldn't doubt that was the reason.

 

[Webb]

Impressive

You and me both brother!!!!

Really though, thanks for all the help everybody. I don't see how so many have been built without the use of VAF!

-Daniel

It is impressive how rapid others took ownership in trying to help and get you on the right track.

I could tell by the tone of your emails that you were almost ready to take off and weren't even in a cockpit!!! (lol)

Will have to say you are moving right along. Have you lined up a partner to help you buck the skins yet cuz it looks like you'll need soon!!!

 

[danielhv]

It is impressive how rapid others took ownership in trying to help and get you on the right track.

I could tell by the tone of your emails that you were almost ready to take off and weren't even in a cockpit!!! (lol)

Will have to say you are moving right along. Have you lined up a partner to help you buck the skins yet cuz it looks like you'll need soon!!!

Yea I was pretty frustrated because I was starring at the plans, then the ribs... then the plans, then the ribs... Took a break, and went back to starring. It wasn't making sense. I was 100% sure of the orientation because vans marked them, I marked them, and then double checked them with the "which side is the flange on" method. I figured if Vans marked a rib w-711L, then its a w-711L for both the L & R wing. Man, I was beside myself with frustration because I couldn't figure this out! But, knowing now that I could just change an L to an R makes it easier... still trying to get used to this whole "thinking in reverse" for the wings.

As far as a bucking partner, I sure do! I've had a number of people come help me when I was getting started that I'm sure wouldn't mind doing some dirty work! After all, you can't fly ALL the time!

Oh and one more thing... MAN I LOVE THIS SITE!!! (Now if I could just find a way to get paid for all the time I spend on here!)

 

[Bob Ellis]

Brain Fart? Yes and No

Daniel

Pleased that it's all resolved. Interpreting 3D drawings is a skill and not every one picks it up straight away. The brain is an odd device and can interpret things in different ways eg is this image a young or an old woman? ....

It is for this reason that behavioural psychologists are often on aircraft accident teams. So don't feel bad - even if you do!

Regards

Bob Ellis
www.rv-8.co.uk